Air shutoff swing gate valve

ABSTRACT

An air shutoff valve includes a passage for supplying air, a swing gate, a shaft attached to a reset handle, and a spring to urge the gate toward its closed position. A trigger assembly secures the shaft and gate in the open position and includes an actuator, a cam, and a rocker arm. A cam surface of the arm has a notch to receive a sear point of the cam. Movement of the handle against the spring causes the cam contact surface of the cam to follow the cam surface to cause the arm to rotate such that the sear point is received in the notch. Actuating the actuator causes the arm to pivot away from the cam such that the sear point is released from the notch, wherein the spring causes the shaft to move the gate to its closed position.

BACKGROUND OF THE INVENTION

The present invention relates to an air shutoff valve, for example, toprevent uncontrolled runaway of the engine.

Diesel engines, in the presence of combustible gases in the atmosphere,occasionally enter a runaway condition in which the engine, without aproper device to mitigate this problem, can enter an uncontrolledacceleration. In this condition, the engine experiences overspeed and,if not stopped, the engine can reach speeds that can result indestruction and/or catastrophic engine failure, and personal injury.There are a number of causes of runaway including, for example, a faultyengine governor, engine overheating or the ingestion of unregulatedhydrocarbons into the combustion chamber through the intake air. Suchhydrocarbons may be from an external source such as airborne gas, orfrom the engine itself due to a malfunction such as failure ofturbocharger oil seals.

A conventional way to stop a diesel engine is to stop the flow of fuelto the combustion chamber. However, an alternate method must be employedto stop a diesel engine in the event of runaway. The most common method,used for many years, involves blocking the air supply to the combustionchamber of the engine. Once deprived of oxygen, the runaway ceases.Accordingly, safety valves which cut off the air supply to the enginehave been developed to shut off the engine in such a situation.

One type of shut-off valve placed in the air intake to the engineemploys a swing gate valve that is spring biased to be in a closedposition that blocks air supply to the combustion chamber. The springloaded valve is held in an open position by a trip mechanism that ismanually cocked to hold the valve in the open position. A solenoid or byother appropriate device may be used to trip the trip mechanism to closethe valve. When in the open position, there is an unobstructed airsupply to the engine. Upon runaway, the device is engaged (ordisengaged), and the valve snaps into its closed position, thus cuttingoff the air supply to the combustion chamber, thereby starving theengine of oxygen such that the engine stalls.

Shutoff valves used in the past were susceptible to damage from highvibration loads and excessively high temperatures. The present inventionprovides improvements to past designs and provides a valve capable ofexperiencing higher vibration and temperature.

All references cited herein are incorporated herein by reference intheir entireties.

BRIEF SUMMARY OF THE INVENTION

An air shutoff swing gate valve for an engine is provided that includesa valve body having an air passage where the air passage is forsupplying air to an engine. The valve includes a valve swing gate thatis pivotable on a swing arm that is pivotally disposed adjacent to thevalve body. The swing gate is pivotable adjacent to the air passage froman open position, wherein the swing gate is positioned adjacent to theair passage to provide for free flow of air through the air passage, toa closed position, wherein the swing gate is positioned within the airpassage to substantially close off the air passage. The valve furtherincludes an actuation assembly having an actuation housing and a triggerassembly. The actuation housing may be integral to the valve body. Theactuation housing is disposed on the valve body. A pivotable shaft isprovided having a longitudinal axis. The shaft extends from theactuation assembly to the swing arm. The swing arm is disposed on theshaft such that rotation of the shaft about its longitudinal axis causesrotation of the swing arm to move the swing gate between its open andclosed positions. A reset handle is disposed on the shaft. Rotation ofthe reset handle rotates the shaft and causes the swing gate to movefrom its closed position to its open position. A spring, such as atorsion spring, rotationally biases the shaft about its longitudinalaxis to urge the swing gate toward its closed position.

The trigger assembly is for securing the shaft such that the swing gateis held in its open position and is also for triggering the shaft torotate due to biasing from the spring. The trigger assembly and biasingspring cause the swing gate to move from the open position to the closedposition. The trigger assembly includes an actuator disposed at a firstend of the actuation housing. The actuator has an actuator shaft. Apivotable cam is disposed in the actuation housing and disposed on thepivotable shaft such that rotation of the pivotable cam causes rotationof the pivotable shaft. The cam has a sear point and a cam contactsurface. A trigger rocker arm is disposed in the actuation housing wherethe trigger rocker arm has a first end pivotally attached to actuatorshaft of the actuator, a second end pivotally attached to a second endof the actuation housing, and a curved cam surface adjacent to thesecond end of the trigger rocker arm. The curved cam surface has a notchto receive the sear point of the cam. The cam surface is for contactingthe cam contact surface such that rotational movement of the resethandle against the bias of the spring causes the cam contact surface ofthe pivotable cam to follow the curved cam surface of the trigger rockerarm to cause the rocker arm to rotate about its second end to a positionwhen the sear point is received in the notch.

Actuation of the actuator to cause movement of the actuator shaft causesthe first end of the rocker arm to move such that the rocker arm pivotsabout the second end of the rocker arm away from the cam such that thesear point of the cam is released from notch of the rocker arm. Thespring then causes the pivotable shaft to rotate about its longitudinalaxis to move the swing gate to its closed position.

The actuator may be, for example, mechanical, electro-mechanical,hydraulic, pneumatic, piezo, or a solenoid. A switch may be providedthat is connected to a display that indicates when the swing gate is inits open and closed positions. The switch may be adjacent to the camwherein rotation of the cam activates and deactivates the switch.

Optionally, a manual override device may be provided to provide formanual tripping of the swing gate. The manual override device mayinclude an override device shaft slidably disposed in an aperture in theactuator housing adjacent to the actuator. The override device shaft issubstantially parallel to an axis of movement of the actuator shaft. Theoverride device shaft has a first end and a second end. The first end isdisposed outside the actuator housing and has a handle for manualmovement of the override device shaft through the aperture. The secondend is disposed adjacent to the first end of the rocker arm, such thatmanual movement of the override device shaft causes substantiallyidentical movement of the rocker arm as the movement caused by theactuator shaft. This manual override can also be applied to the secondembodiment described below.

A second preferred embodiment of the air shutoff swing gate valve of thepresent invention is also provided. This embodiment is directed to avalve that includes a valve body, a valve swing gate, an actuationassembly, a pivotable shaft, a reset handle and a spring as describedabove with respect to the first embodiment. However, in this secondembodiment, the trigger assembly is somewhat different. Here, anactuator is disposed at a first end of the actuation housing, theactuator having an actuator shaft. A pivotable cam is disposed in theactuation housing adjacent to a second end of the actuation housing anddisposed on the pivotable shaft such that rotation of the pivotable camcauses rotation of the pivotable shaft. The cam has a notch and a camsurface. A trigger rocker arm is disposed in the actuation housing. Thetrigger rocker arm has a first end pivotally attached to actuator shaftof the actuator, a central portion pivotally attached to the actuationhousing between the pivotable cam and the actuator, and a sear point anda cam contact surface at a second end of the trigger rocker arm. Thesear point is for receipt in the notch of the cam. The cam surface ofthe cam is for contacting the cam contact surface of the trigger rockerarm. Rotational movement of the reset handle against the bias of thespring causes the cam contact surface of the trigger rocker arm tofollow the cam surface of the cam to cause the rocker arm to rotateabout its central portion to a position until the sear point is receivedin the notch. Actuation of the actuator to cause movement of theactuator shaft causes the first end of the rocker arm to move such thatthe rocker arm pivots about the central portion of the rocker arm tocause the second end of the trigger rocker arm to rotate away from thenotch such that the sear point of the trigger rocker arm is releasedfrom notch of the cam. The spring causes the shaft to rotate about itslongitudinal axis to move the swing gate to its closed position.

The actuator may be, for example, mechanical, electro-mechanical,hydraulic, pneumatic, piezo, or a solenoid. A switch may be providedthat is connected to a display that indicates when the swing gate is inits open and closed positions. The switch may be adjacent to the camwherein rotation of the cam activates and deactivates the switch.

In this second embodiment, a manual override device may be provided formanual tripping of the swing gate. The manual override device mayinclude an override device shaft slidably disposed in an aperture in theactuator housing adjacent to the actuator. The override device shaft iscoaxial with the actuator shaft and has a first end and a second end.The first end is disposed outside the actuator housing and has a handlefor manual movement of the override device shaft through the aperture.The second end is disposed on the actuator shaft such that manualmovement of the override device shaft causes substantially identicalmovement of the rocker arm as the movement caused by the actuator shaft.This manual override can also be applied to the first embodimentdescribed above.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

The invention will be described in conjunction with the followingdrawings in which like reference numerals designate like elements andwherein:

FIG. 1 is a side, elevation view of an air shutoff swing gate valve foran engine in accordance with a first preferred embodiment of the presentinvention;

FIG. 2 is a simplified, cross-sectional view of the air shutoff swingvalve of FIG. 1, taken substantially along lines II-II of FIG. 1;

FIG. 3 is a partial, isometric view of an actuation mechanism of the airshutoff swing gate valve for an engine of FIG. 1, shown with its coverremoved for clarity;

FIG. 4 is a rear, elevation view of the air shutoff swing gate valve foran engine of FIG. 1, shown with the valve in its open position;

FIG. 5 is a front, elevation view of the actuation mechanism of the airshutoff swing gate valve for an engine of FIG. 1, shown with the valvein its open position, shown with its cover removed for clarity;

FIG. 6 is a rear, elevation view of the air shutoff swing gate valve foran engine of FIG. 1, shown with the valve in its closed position;

FIG. 7 is a front, elevation view of the actuation mechanism of the airshutoff swing gate valve for an engine of FIG. 1, shown with the valvein its closed position, shown with its cover removed for clarity;

FIG. 8 is a side, elevation view of an air shutoff swing gate valve foran engine in accordance with a second preferred embodiment of thepresent invention;

FIG. 9 is a rear, isometric view of the air shutoff swing gate valve foran engine of FIG. 8, shown with the valve in its closed position;

FIG. 10 is a rear, isometric view of the air shutoff swing gate valvefor an engine of FIG. 8, shown with the valve in its open position;

FIG. 11 is an isometric view of an actuation mechanism of the airshutoff swing gate valve of FIG. 8;

FIG. 12 is a front isometric view of the actuation mechanism of FIG. 11,shown set for the valve to be in an open position, shown with its coverremoved for clarity; and

FIG. 13 is a front isometric view of the actuation mechanism of FIG. 11,shown set for the valve to be in a closed position, shown with its coverremoved for clarity.

DETAILED DESCRIPTION OF THE INVENTION

The invention will be illustrated in more detail with reference to thefollowing embodiments, but it should be understood that the presentinvention is not deemed to be limited thereto.

First and second preferred embodiments are provided. With respect toboth embodiments, the present invention is directed to a swing gatevalve design for use as an emergency diesel engine air shutoff swinggate valve. The embodiments are designed to operate over a wide range ofon-engine intake air temperatures, ranging from about −40 degrees F.(−40 degrees C.) to about +600 degrees F. (+316 degrees C.), andelevated pressures (about 4 bar gauge) associated with, for example,post-turbocharger, pre-intercooler installation.

The valves provide a complete engine stop by providing an airtightshut-off to the intake manifold, achieved by use of a gate, which isattached to an actuating mechanism by an arm.

The swing gate valves are designed to be assembled as part of an intakemanifold, for use as an emergency diesel engine air intake shutoffvalve. The basic concept of the valve is that it has a manually latchedgate held in the open (i.e., run) position by an actuation mechanism.The open position is defined as the gate being generally outside theintake airflow, allowing the free passage of intake air into the engine.The latched valve remains in the open position until such time as thevalve is tripped, whereby the gate swings under the action of a springinto the closed position, blocking the air flow passage, and creating agenerally airtight seal with the valve body. The restriction created bythe closed valve fully throttles the engine, resulting in engineshutdown.

The design is similar to an existing design by AMOT/RODA DEACO, such asModels 2190 and 2102, with enhancements for use over wider temperaturesand pressures and with an improved, enclosed trigger mechanism. Thetrigger housing is sealed against both the environment and the chargeair pressure.

The gate is preferably made from bronze. The gate is preferably looselyattached to the arm. There is substantially no possibility of fastenersworking loose and entering the intake air stream of the engine. The gateis assembled to the gate arm via a pin, which is contained in place toensure that it does not work loose.

Two seals are preferably used to prevent the charge air from leaking tothe atmosphere or into the trigger housing as the shaft protrudes fromthe valve housing.

The actuation assembly, including the trigger assembly, is containedwithin a separate housing to the valve body. The trigger mechanismcontains a cam and trigger arm that latch together when the gate is inthe open position. The actuation assembly moving parts are connected tothe gate via a linkage mechanism, which allows for manufacturingtolerances and ensures the gate is properly oriented in the open orclosed position.

With respect to the first embodiment of the present valve, electricactuation is preferably used. That is, preferably, an electronicsolenoid provides the actuation force. The trigger mechanism is trippedwhen the solenoid coil is energized and provides the actuation means tothe actuator trigger mechanism. In this configuration, the valve istripped to the closed position, when the solenoid is energized. In analternate design the valve can trip upon loss of charge air pressure.Further, an air cylinder can be utilized as part of a pneumatic actuatorto provide the tripping force. In any case, the mechanism is tripped andthe spring provides the force to rotate the gate into the closedposition once the cam and trigger arm are unlatched. The triggermechanism also preferably incorporates a manual override button tomanually trip the valve. The manual override button is presentregardless of actuation type.

With respect to the second embodiment of the present valve, a pneumaticactuator is preferably used which is an air cylinder and pistonassembly. This actuator provides the actuation means to the actuatortrigger mechanism. In this configuration, the valve is tripped to theclosed position when the air cylinder is pressurized. In an alternatedesign, the valve trips upon loss of air pressure. Alternatively, anelectric solenoid can be utilized to provide the tripping force. In anycase, the mechanism is tripped and a spring provides the force to rotatethe gate into the closed position. Once the cam and trigger arm areunlatched. The trigger mechanism also incorporates a manual overridebutton to manually trip the valve. The manual override button is presentregardless of actuation type.

Various means of installing the air shutoff swing gate valve in placeare possible, such as hump hoses or flanges (bolted, Marmon claims,etc.) by machining the appropriate geometry on the end connections ofthe appropriate body casting.

Both embodiments of the present invention solve numerous problems,including, but not limited to, the following:

-   -   the valve is designed to operate over a wide range of on-engine        intake air temperatures, ranging from −40 degrees F. (−40        degrees C.) to about +600 degrees F. (+316 degrees C.) and        elevated pressures (up to 4 bar gauge) associated with, for        example, post turbocharger, pre-intercooler installation;    -   the valve is designed to operate under the airflow rates for        standard pipe sizes without any obstructions in the flow since        the gate is outside the flowing air while the engine is in        operation;    -   the trigger housing and valve body are sealed, utilizing gaskets        and elastomeric seals;    -   the trigger mechanism requires a low actuation force to trip,        thereby requiring only small pneumatic pressures, or small        electric solenoid forces. This results in reduced valve weight        and minimal envelope dimensions;    -   the use of a gate and arm that are loosely assembled together        prevents the possibility of components working loose and        entering the engine through the intake air stream;    -   use of stainless steel components allows the valve to be used in        corrosive environments;    -   balance in system forces avoids the gate bouncing open on        actuation, permitting undesired air flow to the engine;    -   the valve achieves a fully closed position in less than 1 second        from receipt of a trip signal;    -   the design of the gate and shaft assembly parts to the valve        body allows for no presence of vibration of the gate in the        intake air stream, thereby minimizing the turbulence generation        and resulting in stable engine operation; and    -   a vibration free reset handle and stop device allow for long        lifetime, even in “hard” installations, with no hose        connections.

The air shutoff swing gate valve of the present invention is designed tobe assembled as part of the intake manifold of diesel engine. The basicconcept of the valve is that it utilizes a manually latched gate held inthe open (or run) position by an actuation trigger mechanism. The openor run position means that the swing gate allows for free passage ofintake air into the engine. The latched valve remains in the openposition until such time as the valve is tripped, whereby the swing gaterotates, under the action of a spring, creating an airtight seal withthe valve body. The restriction created by the closed disc fullythrottles the engine, resulting in an engine shut down.

Referring now to the drawing figures, wherein like part numbers refer tolike elements throughout the several views, there is shown in FIGS. 1-7an air shutoff swing gate valve 10 for an engine in accordance with afirst preferred embodiment of the present invention. The air shutoffswing gate valve 10 generally includes a valve body 12, a valve swinggate 14, an actuation assembly 16, a pivotable shaft 18, a reset handle20, and a spring 22 (for example, a torsion spring, as shown).

The valve body 12 has an air passage 24 therein for supplying air to anengine to which the air shutoff valve 10 is attached. The swing gate 14is pivotable on a swing arm 26 that is pivotally disposed. The swinggate 14 is pivotable from an open position (see FIG. 4) wherein theswing gate 14 is positioned adjacent to the air passage 24 to providefor free flow of air through the air passage 24, to a closed position(see FIG. 6) wherein the swing gate 14 is positioned within the airpassage 24 to substantially close off the air passage 24. The actuationassembly 16 includes an actuation housing 28 and a trigger assembly 30.The actuation housing 28 is preferably disposed on the valve body 12 byfasteners 32 (e.g. the threaded holes shown in combination with screws).

The pivotable shaft 18 has a longitudinal axis A (see FIG. 1) andextends from the actuation assembly 16 at least to the swing arm 26. Theswing arm 26 is disposed on the shaft 18 such that rotation of the shaft18 about its longitudinal axis A causes rotation of the swing arm 26 tomove the swing gate 14 between its open (see FIG. 4) and closedpositions (see FIG. 6). The reset handle 20 is disposed on the shaft 18such that rotation of the reset handle 20 to rotate the shaft 18 causesthe swing gate 14 to move from its closed position to its open position.The spring 22 rotationally biases the shaft 18 about its longitudinalaxis A to urge the swing gate 14 toward its closed position.

The trigger assembly 30 is for securing shaft 18 such that the swinggate 14 is held in its open position (see FIG. 4) and for triggering theshaft 18 to rotate due to biasing from the spring 22 to cause the swinggate 14 to move from the open position to the closed position. Thetrigger assembly 30 generally includes an actuator 36 (preferablylinear), a pivotable cam 38, and a trigger rocker arm 40 (see FIGS. 3, 5and 7). The actuator 36 is disposed at a first end 42 of the actuationhousing 28 and has an actuator shaft 44. The pivotable cam 38 isdisposed in the actuation housing 28 and is disposed on the pivotableshaft 18 such that rotation of the pivotable cam 38 causes rotation ofthe pivotable shaft 18. The pivotable cam 38 also has a sear point 46and a cam contact surface 48. The trigger rocker arm 40 is disposed inthe actuation housing 28 and has a first end 50 pivotally attached toactuator shaft 44 of the actuator 36, a second end 52 pivotally attachedto a second end 54 of the actuation housing 28, and a curved cam surface56 adjacent to the second end 52 of the trigger rocker arm 40. Thecurved cam surface 56 has a notch 58 (best seen in FIG. 7) to receivethe sear point 46 of the cam 38. The cam surface 56 of the triggerrocker arm 40 is for contacting the cam contact surface 48 of the cam 38such that rotational movement of the reset handle 20 against the bias ofthe spring 22 causes the cam contact surface 48 of the pivotable cam 38to follow the cam surface 56 of the trigger rocker arm 40 to cause therocker arm 40 to rotate about its second end 52 to a position when thesear point 46 is received in the notch 58. See FIGS. 1, 2, 4 and 6.

Actuation of the actuator 36 to cause (preferably, but not limited to,linear) movement of the actuator shaft 44 causes the first end 50 of therocker arm 40 to move such that the rocker arm 40 pivots about thesecond end 52 of the rocker arm 40 away from the cam 38 such that thesear point 46 of the cam 38 is released from notch 58 of the rocker arm40, thereby allowing the spring 22 to cause the pivotable shaft 18 torotate about its longitudinal axis to move the swing gate to its closedposition.

The actuator 36 may be of substantially any type. It is preferably alinear actuator, but any actuator or solenoid or similar device thatprovides an appropriate movement of the rocker arm 40 is considered tobe within the scope of the present invention. For example, mechanical,electro-mechanical, solenoid, hydraulic, pneumatic, and piezo actuatorscould all work appropriately.

A switch 60 may be provided that is connected to a display to indicatewhen the swing gate 14 is in its open and closed positions. The switch60 may be, for example, adjacent to the cam 38 wherein rotation of thecam 38 activates and deactivates the switch 60. The switch 60 may be,for example, an electro-magnetic switch, a mechanical switch orHall-effect switch.

A manual override device 62 may be provided to trip the trigger assembly30 to manually cause the swing gate 14 to move to the closed position toblock air to the engine. The manual override device 62 includes anoverride device shaft 64 slidably disposed in an aperture in theactuator housing 28 adjacent to the actuator 36. The override deviceshaft 64 is substantially parallel to an axis of movement of theactuator shaft 44. The override device shaft 64 has a first end 68 and asecond end 70. The first end 68 is disposed outside the actuator housing28 and has a handle 72 for manual movement of the override device shaft64 through the aperture. The second end 70 is disposed adjacent to thefirst end 50 of the rocker arm 40 such that manual movement of theoverride device shaft 64 causes substantially identical movement of therocker arm 40 as the movement caused by the actuator shaft 44. Themanual override device 62 may be biased by a spring 74 to a positionwhere it does not contact the rocker arm 40.

There is shown in FIGS. 8-13 an air shutoff swing gate valve 110 for anengine in accordance with a second preferred embodiment of the presentinvention. The air shutoff swing gate valve 110 generally includes avalve body 112, a valve swing gate 114, an actuation assembly 116, apivotable shaft 118, a reset handle 120, and a spring 122.

The valve body 112 has an air passage 124 therein for supplying air toan engine to which the air shutoff valve 110 is attached. The swing gate114 is pivotable on a swing arm 126 that is pivotally disposed adjacentto the valve body 112. The swing gate 14 is pivotable from an openposition (see FIG. 10) wherein the swing gate 114 is positioned adjacentto the air passage 124 to provide for free flow of air through the airpassage 124, to a closed position (see FIG. 9) wherein the swing gate114 is positioned within the air passage 124 to substantially close offthe air passage 124. The actuation assembly 116 includes an actuationhousing 128 and a trigger assembly 130. The actuation housing 128 ispreferably disposed on the valve body 112 by fasteners 132.

A pivotable shaft 118 has a longitudinal axis B (see FIG. 11) andextends from the actuation assembly 116 at least to the swing arm 126.The swing arm 126 is disposed on the shaft 118 such that rotation of theshaft 118 about its longitudinal axis B causes rotation of the swing arm126 to move the swing gate 114 between its open (see FIG. 10) and closedpositions (see FIG. 9). The reset handle 120 is disposed on the shaft118 such that rotation of the reset handle 120 to rotate the shaft 118causes the swing gate 114 to move from its closed position to its openposition. The spring 122 rotationally biases the shaft 118 about itslongitudinal axis B to urge the swing gate 114 toward its closedposition (see FIG. 9).

The trigger assembly 130 is for securing shaft 118 such that the swinggate 114 is held in its open position (see FIG. 10) and for triggeringthe shaft 118 to rotate due to biasing from the spring 122 to cause theswing gate 114 to move from the open position to the closed position(see FIG. 9). As can best be seen in FIGS. 12 and 13, the triggerassembly 130 generally includes an actuator 136 (preferably linear), apivotable cam 138, and a trigger rocker arm 140. The actuator 136 isdisposed at a first end 142 of the actuation housing 128 and has anactuator shaft 144. The pivotable cam 138 is disposed in the actuationhousing 128 and is disposed on the pivotable shaft 118 such thatrotation of the pivotable cam 138 causes rotation of the pivotable shaft118. The pivotable cam 138 also has a notch 158 and a cam surface 156.The trigger rocker arm 140 is disposed in the actuation housing 128 andhas a first end 150 pivotally attached to actuator shaft 144 of theactuator 136. The trigger rocker arm 140 also has a central portion 147pivotally attached to the actuation housing 128 between the pivotablecam 138 and the actuator 136. Finally, the trigger rocker arm has thesear point 146 and the cam contact surface 148 at its second end 152.The sear point 146 is for receipt in the notch 158 of the cam 138. Thecam surface 156 of the pivotable cam 138 is for contacting the camcontact surface 148 of the trigger rocker arm 140 such that manualrotational movement of the reset handle 120 against the bias of thespring 122 causes the cam contact surface 148 of the trigger rocker arm140 to follow the cam surface 156 of the pivotable cam 138 to cause therocker arm 140 to rotate about its central portion 147 to a positionuntil the sear point 146 is received and held in the notch 158.

Actuation of the actuator 136 to cause linear movement of the actuatorshaft 144 causes the first end 150 of the rocker arm 140 to move suchthat the rocker arm 140 pivots about the central portion 147 of therocker arm 140 to cause the second end 152 of the rocker arm 140 torotate away from the notch 158 such that the sear point 146 of thetrigger rocker arm 140 is released from notch 158 of the cam 138,wherein the spring 122 causes the shaft 118 to rotate about itslongitudinal axis 13 to move the swing gate 114 to its closed position.

Again, the actuator 136 may be of substantially any type. It ispreferably a linear actuator, but any actuator or solenoid or similardevice that provides an appropriate movement of the rocker arm 140 isconsidered to be within the scope of the present invention. For example,mechanical, electro-mechanical, hydraulic, pneumatic, and piezoactuators could all work appropriately.

A switch 160 may be provided that is connected to a display to indicatewhen the swing gate 114 is in its open and closed positions. The switch160 may be adjacent to the cam 138 wherein rotation of the cam 138activates and deactivates the switch 160. The switch 160 may be, forexample, an electromagnetic switch, a mechanical switch, or Hall-effectswitch.

A manual override device 162 may be provided to trip the triggerassembly 130 to provide for manual tripping of the swing gate 114 tomove it to the closed position to block air to the engine. The manualoverride device 162 includes an override device shaft 164 slidablydisposed in an aperture in the actuator housing 128 adjacent to theactuator 136. The override device shaft 164 is coaxial with the actuatorshaft 144. The override device shaft 164 has a first end 168 and asecond end 170. The first end 168 is disposed outside the actuatorhousing 128 and has a handle 172 (or button or any portion available tomanually grip) for manual movement of the override device shaft 164through the aperture. The second end 170 is disposed on the actuatorshaft 144 such that manual movement of the override device shaft 144causes substantially identical movement of the rocker arm 140 as themovement caused by the actuator shaft 144.

With respect to both embodiments, preferably, the valve body 12, 112 isaluminum, but any suitable material may be used. Preferably, Marmonflanges may be used to connect the valve 10 to the engine, however, anysuitable flange may be used. Preferably, the gate is manufactured frombronze alloy.

The present invention operates in either “hard installations,” such asintegral with aluminum piping, or “soft installations,” such as alongrubber hoses. Each of the improvements described herein helps the valveto operate in high vibration and temperature environments.

While the present invention has been described primarily with respect toan engine, such as a diesel engine, the present invention is notintended to be limited only to engines. It is intended to apply tosubstantially any application where a cutoff valve could be used, evenincluding, for example, a water cutoff supply.

While the invention has been described in detail and with reference tospecific embodiments thereof, it will be apparent to one skilled in theart that various changes and modifications can be made therein withoutdeparting from the spirit and scope thereof.

What is claimed is:
 1. An air shutoff swing gate valve, comprising: (a)a valve body having an air passage therein, the air passage forsupplying air; (b) a valve swing gate, pivotable on a swing arm that ispivotally disposed adjacent to the valve body, the swing gate pivotableadjacent to the air passage from an open position wherein the swing gateis positioned adjacent to the air passage to provide for free flow ofair through the air passage, to a closed position wherein the swing gateis positioned within the air passage to substantially close off the airpassage; (c) an actuation assembly comprising an actuation housing and atrigger assembly, the actuation housing disposed on the valve body; (d)a pivotable shaft having a longitudinal axis, the shaft extending atleast from the actuation assembly to the swing arm, the swing armdisposed on the shaft such that rotation of the shaft about itslongitudinal axis causes rotation of the swing arm, to move the swinggate between its open and closed positions; (e) a reset handle disposedon the shaft, such that rotation of the reset handle to rotate the shaftcauses the swing gate to move from its closed position to its openposition; (f) a spring to rotationally bias the shaft about itslongitudinal axis to urge the swing gate toward its closed position; (g)the trigger assembly for securing the shaft such that the swing gate isheld in its open position and for triggering the shaft to rotate due tobiasing from the spring to cause the swing gate to move from the openposition to the closed position, the trigger assembly comprising: (i) anactuator disposed at a first end of the actuation housing, the actuatorhaving an actuator shaft; (ii) a pivotable cam disposed in the actuationhousing and disposed on the pivotable shaft such that rotation of thepivotable cam causes rotation of the pivotable shaft, the cam having asear point and a cam contact surface; and (iii) a trigger rocker armdisposed in the actuation housing, the trigger rocker arm having a firstend pivotally attached to actuator shaft of the actuator, a second endpivotally attached to a second end of the actuation housing, a curvedcam surface adjacent to the second end of the trigger rocker arm, thecurved cam surface having a notch to receive the sear point of the cam,the cam surface for contacting the cam contact surface of the cam suchthat rotational movement of the reset handle against the bias of thespring causes the cam contact surface of the pivotable cam to follow thecurved cam surface of the trigger rocker arm to cause the rocker arm torotate about its second end to a position when the sear point isreceived in the notch; and (h) wherein actuation of the actuator tocause linear movement of the actuator shaft causes the first end of therocker arm to move such that the rocker arm pivots about the second endof the rocker arm away from the cam such that the sear point of the camis released from notch of the rocker arm, wherein the spring causes thepivotable shaft to rotate about its longitudinal axis to move the swinggate to its closed position.
 2. The air shutoff swing gate valve ofclaim 1, wherein the actuator is of a type selected from the groupconsisting of mechanical, electro-mechanical, hydraulic, pneumatic, andpiezo.
 3. The air shutoff swing gate valve of claim 1, wherein theactuator is a solenoid.
 4. The air shutoff swing gate valve of claim 1,further comprising a switch connected to a display that indicates whenthe swing gate is in its open and closed positions.
 5. The air shutoffswing gate valve of claim 4, wherein the switch is adjacent to the camand wherein rotation of the cam activates and deactivates the switch. 6.The air shutoff swing gate valve of claim 1, further including a manualoverride device to provide for manual tripping of the swing gate,comprising an override device shaft slidably disposed in an aperture inthe actuator housing adjacent to the actuator, the override device shaftbeing substantially parallel to an axis of movement of the actuatorshaft, the override device shaft having a first end and a second end,the first end disposed outside the actuator housing and having a handlefor manual movement of the override device shaft through the aperture,the second end disposed adjacent to the first end of the rocker arm,such that manual movement of the override device shaft causessubstantially identical movement of the rocker arm as the movementcaused by the actuator shaft.
 7. The air shutoff swing gate valve ofclaim 1, further including a manual override device to provide formanual tripping of the swing gate, comprising an override device shaftslidably disposed in an aperture in the actuator housing adjacent to theactuator, the override device shaft being coaxial with the actuatorshaft, the override device shaft having a first end and a second end,the first end disposed outside the actuator housing and having a handlefor manual movement of the override device shaft through the aperture,the second end disposed on the actuator shaft, such that manual movementof the override device shaft causes substantially identical movement ofthe rocker arm as the movement caused by the actuator shaft.
 8. An airshutoff swing gate valve, comprising: (a) a valve body having an airpassage therein, the air passage for supplying air; (b) a valve swinggate, pivotable on a swing arm that is pivotally disposed adjacent tothe valve body, the swing gate pivotable within the air passage from anopen position wherein the swing gate is positioned adjacent to the airpassage to provide for free flow of air through the air passage, to aclosed position wherein the swing gate is positioned within the airpassage to substantially close off the air passage; (c) an actuationassembly comprising an actuation housing and a trigger assembly, theactuation housing disposed on the valve body; (d) a pivotable shafthaving a longitudinal axis, the shaft extending from the actuationassembly at least to the swing arm, the swing arm disposed on the shaftsuch that rotation of the shaft about its longitudinal axis causesrotation of the swing arm, to move the swing gate between its open andclosed positions; (e) a reset handle disposed on the shaft, such thatrotation of the reset handle to rotate the shaft causes the swing gateto move from its closed position to its open position; (f) a spring torotationally bias the shaft about its longitudinal axis to urge theswing gate toward its closed position; (g) the trigger assembly forsecuring the shaft such that the swing gate is held in its open positionand for triggering the shaft to rotate due to biasing from the spring tocause the swing gate to move from the open position to the closedposition, the trigger assembly comprising: (i) an actuator disposed at afirst end of the actuation housing, the actuator having an actuatorshaft; (ii) a pivotable cam disposed in the actuation housing adjacentto a second end of the actuation housing and disposed on the pivotableshaft such that rotation of the pivotable cam causes rotation of thepivotable shaft, the cam having a notch and a cam surface; and (iii) atrigger rocker arm disposed in the actuation housing, the trigger rockerarm having a first end pivotally attached to actuator shaft of theactuator, a central portion pivotally attached to the actuation housingbetween the pivotable cam and the actuator, and a sear point and a camcontact surface at a second end of the trigger rocker arm, the searpoint for receipt in the notch of the cam, the cam surface of the camfor contacting the cam contact surface of the trigger rocker arm suchthat rotational movement of the reset handle against the bias of thespring causes the cam contact surface of the trigger rocker arm tofollow the cam surface of the cam to cause the rocker arm to rotateabout its central portion to a position until the sear point is receivedin the notch; and (h) wherein actuation of the actuator to cause linearmovement of the actuator shaft causes the first end of the rocker arm tomove such that the rocker arm pivots about the central portion of therocker arm to cause the second end of the trigger rocker arm to rotateaway from the notch such that the sear point of the trigger rocker armis released from notch of the cam, wherein the spring causes the shaftto rotate about its longitudinal axis to move the swing gate to itsclosed position.
 9. The air shutoff swing gate valve of claim 8, whereinthe actuator is of a type selected from the group consisting ofmechanical, electro-mechanical, hydraulic, pneumatic, and piezo.
 10. Theair shutoff swing gate valve of claim 8, wherein the actuator is asolenoid.
 11. The air shutoff swing gate valve of claim 8, furthercomprising a switch connected to a display that indicates when the swinggate is in its open and closed positions
 12. The air shutoff swing gatevalve of claim 11, wherein the switch is adjacent to the cam and whereinrotation of the cam activates and deactivates the switch.
 13. The airshutoff swing gate valve of claim 8, further including a manual overridedevice to provide for manual tripping of the swing gate, comprising anoverride device shaft slidably disposed in an aperture in the actuatorhousing adjacent at least to the actuator, the override device shaftbeing coaxial with the actuator shaft, the override device shaft havinga first end and a second end, the first end disposed outside theactuator housing and having a handle for manual movement of the overridedevice shaft through the aperture, the second end disposed on theactuator shaft, such that manual movement of the override device shaftcauses substantially identical movement of the rocker arm as themovement caused by the actuator shaft.
 14. The air shutoff swing gatevalve of claim 8, further including a manual override device to providefor manual tripping of the swing gate, comprising an override deviceshaft slidably disposed in an aperture in the actuator housing adjacentto the actuator, the override device shaft being substantially parallelto an axis of movement of the actuator shaft, the override device shafthaving a first end and a second end, the first end disposed outside theactuator housing and having a handle for manual movement of the overridedevice shaft through the aperture, the second end disposed adjacent tothe first end of the rocker arm, such that manual movement of theoverride device shaft causes substantially identical movement of therocker arm as the movement caused by the actuator shaft.
 15. In an airshutoff swing gate valve having a valve swing gate pivotable from anopen position to provide for free flow of air through the air passage toa closed position to substantially close off the air passage, anactuation assembly, a pivotable shaft extending from the actuationassembly at least to the swing arm, a reset handle to rotate the shaftto cause the swing gate to move from its closed position to its openposition, a spring to rotationally bias the shaft about its longitudinalaxis to urge the swing gate toward its closed position, a triggerassembly for securing the shaft such that the swing gate is held in itsopen position and for triggering the shaft to rotate due to biasing fromthe spring to cause the swing gate to move from the open position to theclosed position, the trigger assembly comprising: (a) an actuator havingan actuator shaft; (b) a pivotable cam disposed on the pivotable shaftsuch that rotation of the pivotable cam causes rotation of the pivotableshaft, the cam having a sear point and a cam contact surface; and (c) atrigger rocker arm having a first end pivotally attached to actuatorshaft of the actuator, a second end that is free to pivot, a curved camsurface adjacent to the second end of the trigger rocker arm, the curvedcam surface having a notch to receive the sear point of the cam, the camsurface for contacting the cam contact surface of the cam such thatrotational movement of the reset handle against the bias of the springcauses the cam contact surface of the pivotable cam to follow the curvedcam surface of the trigger rocker arm to cause the rocker arm to rotateabout its second end to a position when the sear point is received inthe notch; and wherein actuation of the actuator to cause linearmovement of the actuator shaft causes the first end of the rocker arm tomove such that the rocker arm pivots about the second end of the rockerarm away from the cam such that the sear point of the cam is releasedfrom notch of the rocker arm, wherein the spring causes the pivotableshaft to rotate about its longitudinal axis to move the swing gate toits closed position.
 16. The trigger assembly of claim 15, furtherincluding a manual override device to provide for manual tripping of theswing gate, comprising a slidably disposed override device adjacent tothe actuator, the override device shaft being substantially parallel toan axis of movement of an actuator shaft of the actuator, the overridedevice shaft having a handle for manual movement of the override deviceshaft, the second end disposed adjacent to the first end of the rockerarm, such that manual movement of the override device shaft causessubstantially identical movement of the rocker arm as the movementcaused by the actuator shaft.
 17. The trigger assembly of claim 15,further including a manual override device to provide for manualtripping of the swing gate, comprising a slidably disposed overridedevice shaft adjacent to the actuator, the override device shaft beingcoaxial with the actuator shaft, the override device shaft having afirst end having a handle for manual movement of the override deviceshaft and a second end disposed on the actuator shaft, such that manualmovement of the override device shaft causes substantially identicalmovement of the rocker arm as the movement caused by the actuator shaft.18. In an air shutoff swing gate valve having a valve swing gatepivotable from an open position to provide for free flow of air throughthe air passage to a closed position to substantially close off the airpassage, an actuation assembly, a pivotable shaft extending from theactuation assembly to the swing arm, a reset handle to rotate the shaftto cause the swing gate to move from its closed position to its openposition, a spring to rotationally bias the shaft about its longitudinalaxis to urge the swing gate toward its closed position, a triggerassembly for securing the shaft such that the swing gate is held in itsopen position and for triggering the shaft to rotate due to biasing fromthe spring to cause the swing gate to move from the open position to theclosed position, the trigger assembly comprising: (a) an actuator havingan actuator shaft; (b) a pivotable cam disposed on the pivotable shaftsuch that rotation of the pivotable cam causes rotation of the pivotableshaft, the cam having a notch and a cam surface; and (c) a triggerrocker arm having a first end pivotally attached to actuator shaft ofthe actuator, a central portion free to pivot disposed between thepivotable cam and the actuator, and a sear point and a cam contactsurface at a second end of the trigger rocker arm, the sear point forreceipt in the notch of the cam, the cam surface of the cam forcontacting the cam contact surface of the trigger rocker arm such thatrotational movement of the reset handle against the bias of the springcauses the cam contact surface of the trigger rocker arm to follow thecam surface of the cam to cause the rocker arm to rotate about itscentral portion to a position until the sear point is received in thenotch; and wherein actuation of the actuator to cause linear movement ofthe actuator shaft causes the first end of the rocker arm to move suchthat the rocker arm pivots about the central portion of the rocker armto cause the second end of the trigger rocker arm to rotate away fromthe notch such that the sear point of the trigger rocker arm is releasedfrom notch of the cam, wherein the spring causes the shaft to rotateabout its longitudinal axis to move the swing gate to its closedposition.
 19. The trigger assembly of claim 18, further including amanual override device to provide for manual tripping of the swing gate,comprising a slidably disposed override device shaft adjacent to theactuator, the override device shaft being coaxial with the actuatorshaft, the override device shaft having a first end having a handle formanual movement of the override device shaft and a second end disposedon the actuator shaft, such that manual movement of the override deviceshaft causes substantially identical movement of the rocker arm as themovement caused by the actuator shaft.
 20. The trigger assembly of claim18, further including a manual override device to provide for manualtripping of the swing gate, comprising a slidably disposed overridedevice adjacent to the actuator, the override device shaft beingsubstantially parallel to an axis of movement of an actuator shaft ofthe actuator, the override device shaft having a handle for manualmovement of the override device shaft, the second end disposed adjacentto the first end of the rocker arm, such that manual movement of theoverride device shaft causes substantially identical movement of therocker arm as the movement caused by the actuator shaft.